The state Attorney General’s office has agreed to conduct a criminal investigation into whether Multnomah County board Chairman Jeff Cogen broke any state laws in pursuit of his affair with Sonia Manhas.

The move comes after Multnomah County District Attorney Rod Underhill and Sheriff Dan Staton asked for a “DA’s Assist” in looking into the case.

Jeff Manning, a Department of Justice spokesman, explained the probe by saying, “They are always criminal and it’s always people from the Criminal Justice Division who do these. That’s the way it will be on this one, too.”

“This is a big, high priority,” he said. “It’ll begin soon, if not today. In terms of how long it will take, I don’t think anybody knows.”

In their letter, Underhill and Staton wrote, “Given the attention this issue has received throughout Multnomah County, both the district attorney and the sheriff want to ensure that the matter receives a completely fair and impartial review by an outside agency.

“It’s important to note that this investigation will determine whether any Oregon criminal laws were broken.”

In a separate development, the four commissioners asked for an outside look into whether the 51-year-old board chairman broke any state laws by spending money to travel to Atlanta twice for conferences.

The first time, he and Manhas, 40, traveled together and spent nights at an area hotel. Both were reimbursed by the county.

Cogen traveled alone for the second conference, earlier this year, but was joined at an Atlanta hotel by Manhas, who was taking a vacation at the time.

So far, Cogen has said he will not resign. He confessed to the affair last week.